Nigella Lawson's former assistants say they feel no guilt about forcing the celebrity chef to confess to drug use.

Italian sistersFrancesca and Elisabetta Grillo were acquitted of fraudulently using company credits cards and spending hundreds of thousands of pounds on designer goods for themselves while working as personal assistants to Lawson and her ex-husband Charles Saatchi.

The Grillo sisters said every purchase had been approved by their former bosses.

Jurors at a London court found the pair not guilty of the charges after deliberating for nine hours.

They said while it had been "tough" for Lawson to spend two days in the witness box at their fraud trial, it was harder for them not knowing if they were to be jailed.

"I feel sorry that we ended up in that situation; that she did admit to that.

"But no, not guilty, because it was nothing to do with me; it's her life."

Lawson admitted during the trial that she took cocaine with her late husband John Diamond when he found out he had terminal cancer, and in 2010 when she claimed she was being ''subjected to intimate terrorism" by Saatchi.

Police are to review her admission that she took the prohibited drug.

Francesca said Lawson was brave to admit her drug use, but that was not why they were in court.

''I felt sorry for all of us involved, we shouldn't have reached that, but unfortunately you're in a position where your freedom is at stake so you have to tell your side of the story.

"It is a bit of a pity we ended up in there to be honest, I wish it didn't happen.''

While the sisters won their legal battle, they said Lawson won the hearts of the British public.

"We have won the court case but definitely she had the most support from the public," Francesca said.

"She is well loved and she will always be loved and I am sure she will be fine. She is great at what she is doing and I wish her all the best."